When an entire family is murdered near the small town of Alva, Kansas, two things strike Deputy U.S. Marshal Jack Slade: first, that he'll be riding out to Alva in the morning, and second, that there was no apparent reason for the crime. ... The killer calls himself the Prophet, and the word he brings is death. He sends his Avenging Angels to execute his chosen list of sinners. Until he calls down the wrath of Jack Slade, who does his preaching with bullets.